Ibn `Abbas, Mujahid, `Ikrimah, Ad-Dahhak and several others said that those mentioned in the Ayah are the three who were made to wait to know if their repentance was accepted; Mararah bin Ar-Rabi`, Ka`b bin Malik and Hilal bin Umayyah. Some Companions stayed behind from the battle of Tabuk due to laziness, preferring comfort, ease, ripe fruits and shade. They did not lag behind because of hypocrisy or doubts. Some of them tied themselves to the pillars (of the Masjid) like Abu Lubabah and several of his friends did. Some of them did not do that, and they are the three mentioned here. Those who tied themselves received their pardon before these three men whose pardon was delayed, until this Ayah was revealed,

[لَقَدْ تَابَ الله عَلَى النَّبِىِّ وَالْمُهَـجِرِينَ وَالاٌّنصَـرِ]

(Allah has forgiven the Prophet, the Muhajirin and the Ansar...)

[وَعَلَى الثَّلَـثَةِ الَّذِينَ خُلِّفُواْ حَتَّى إِذَا ضَاقَتْ عَلَيْهِمُ الأَرْضُ بِمَا رَحُبَتْ]

(And the three who stayed behind, until for them the earth, vast as it is, was straitened...) We will mention the Hadith about this story from Ka`b bin Malik. Allah said,

[إِمَّا يُعَذِّبُهُمْ وَإِمَّا يَتُوبُ عَلَيْهِمْ]

(whether He will punish them or will forgive them. ) meaning, they are at Allah's mercy, if He wills, He pardons them or punishes them. However, Allah's mercy comes before His anger,

[وَاللَّهُ عَلِيمٌ حَكِيمٌ]

(And Allah is All-Knowing, All-Wise.) [9:106] Allah knows those who deserve the punishment and those who deserve the pardon. He is All-Wise in His actions and statements, there is no deity worthy of worship nor Lord besides Him.

[وَالَّذِينَ اتَّخَذُواْ مَسْجِدًا ضِرَارًا وَكُفْرًا وَتَفْرِيقًا بَيْنَ الْمُؤْمِنِينَ وَإِرْصَادًا لِّمَنْ حَارَبَ اللَّهَ وَرَسُولَهُ مِن قَبْلُ وَلَيَحْلِفَنَّ إِنْ أَرَدْنَا إِلاَّ الْحُسْنَى وَاللَّهُ يَشْهَدُ إِنَّهُمْ لَكَـذِبُونَ - لاَ تَقُمْ فِيهِ أَبَدًا لَّمَسْجِدٌ أُسِّسَ عَلَى التَّقْوَى مِنْ أَوَّلِ يَوْمٍ أَحَقُّ أَن تَقُومَ فِيهِ فِيهِ رِجَالٌ يُحِبُّونَ أَن يَتَطَهَّرُواْ وَاللَّهُ يُحِبُّ الْمُطَّهِّرِينَ ]

(107. And as for those who put up a Masjid by way of harm and disbelief and to disunite the believers and as an outpost for those who warred against Allah and His Messenger aforetime, they will indeed swear that their intention is nothing but good. Allah bears witness that they are certainly liars.) (108. Never stand you therein. Verily, the Masjid whose foundation was laid from the first day on Taqwa is more worthy that you stand therein (to pray). In it are men who love to clean and purify themselves. And Allah loves those who make themselves clean and pure.)